Work vehicle with row unit having variable steering angle

ABSTRACT

A row unit for a work vehicle includes a row unit frame with a closer frame. The closer frame defines a longitudinal axis and a transverse axis. The closer frame is supported for rotational movement about a substantially vertical steering axis to vary a turning angle between the longitudinal axis the vehicle longitudinal axis. The row unit includes a closer implement assembly with first and second closer implements and a walking beam construction. The first and second closer implements are attached to opposite areas of the walking beam construction. The walking beam construction is rotationally attached to the closer frame to support rotation of the closer implement assembly about the transverse axis. The first and second closer implements are configured to move ground material into a ground opening from opposites sides as the work vehicle moves across the field.

CROSS-REFERENCE TO RELATED APPLICATION(S)

Not applicable.

STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE DISCLOSURE

This disclosure relates to work vehicles, such as planters and seeders,and, more particularly, relates to a work vehicle with one or morerotatable row units having a variable steering angle.

BACKGROUND OF THE DISCLOSURE

Some work vehicles are configured for applying seed, fertilizer, and/orother particulate commodities to a field. Oftentimes, the work vehiclemay include a metering system, which meters out a predetermined amountof the commodity for delivery to the soil. The work vehicle may alsoinclude a plurality of row units with ground engaging implements thatare configured to receive the metered commodity and plant it within thesoil.

More specifically, as the work vehicle moves across the field, theground engaging implement(s) of a row unit may create a trench or furrowin the soil. The row unit may deliver the commodity into the trench.Then, the ground engaging implement(s) may move the soil over thecommodity and bury the commodity under the surface of the soil.

SUMMARY OF THE DISCLOSURE

This disclosure provides a work vehicle with an improved row unit forimproved planting, seeding, fertilizing, and related processes.

In one aspect, the disclosure provides a row unit for a work vehicle.The work vehicle defines a vehicle longitudinal axis. The row unit isconfigured to be attached to the work vehicle with a plurality of otherrow units for movement across a field. The row unit includes a row unitframe including a closer frame. The closer frame defines a longitudinalaxis and a transverse axis. The closer frame is supported for rotationalmovement about a substantially vertical steering axis to vary a turningangle between the longitudinal axis of the closer frame and the vehiclelongitudinal axis. Furthermore, the row unit includes a closer implementassembly that includes a first closer implement, a second closerimplement, and a walking beam construction. The first closer implementand the second closer implement are attached to opposite areas of thewalking beam construction. The walking beam construction is rotationallyattached to the closer frame to support rotation of the closer implementassembly about the transverse axis. The first closer implement isconfigured to move ground material into a ground opening from one sideas the work vehicle moves across the field. The second closer implementis configured to move ground material into the ground opening from anopposite side as the work vehicle moves across the field.

In another aspect, the disclosure provides a row unit for a workvehicle. The row unit is configured to be attached to the work vehiclewith a plurality of other row units for movement across a field. The rowunit includes a forward frame defining a forward longitudinal axis. Theforward frame is configured to attach to a work vehicle frame of thework vehicle. The row unit also includes a closer frame defining acloser longitudinal axis. The closer frame is rotationally attached tothe forward frame and is supported for rotational movement about asubstantially vertical steering axis to vary a turning angle between thecloser longitudinal axis and the forward longitudinal axis. Moreover,the row unit includes a closer implement attached to the closer frame.The closer implement is configured to move ground material into a groundopening as the work vehicle moves across the field. The closer frame issupported for movement relative to the forward frame between anunrestrained position and a restrained position. The closer frame, inthe unrestrained position, is supported for rotational movement aboutthe steering axis to vary the turning angle. The closer frame, in therestrained position, is restrained at a substantially fixed turningangle.

In a further aspect, the disclosure provides a work vehicle configuredfor movement across a field. The work vehicle includes a work vehicleframe and a plurality of row units that are attached to the work vehicleframe. At least one row unit includes a forward frame that supports anopener implement. The opener implement is configured to open a trench asthe work vehicle moves across the field. The forward frame defines aforward longitudinal axis. The forward frame includes a retainerprojection. The row unit also includes a closer frame defining a closerlongitudinal axis. The closer frame includes a linkage and a trailingframe. The linkage is rotationally attached to the forward frame about asubstantially vertical steering axis. The trailing frame is rotationallyattached to the linkage about a lateral axis. The linkage is configuredto rotate about the steering axis to vary a turning angle between thecloser longitudinal axis and the forward longitudinal axis. The row unitadditionally includes a closer implement assembly having a first closerimplement, a second closer implement, and a walking beam construction.The first closer implement and the second closer implement are attachedto opposite areas of the walking beam construction. The walking beamconstruction is rotationally attached to the trailing frame to supportrotation of the closer implement assembly about a walking beamtransverse axis. The first closer implement is configured to move groundmaterial into the trench from one side as the work vehicle moves acrossthe field, and the second closer implement is configured to move groundmaterial into the trench from an opposite side as the work vehicle movesacross the field. The trailing frame is supported for rotationalmovement about the lateral axis relative to the forward frame between anunrestrained position and a restrained position. The trailing frame, inthe unrestrained position, is spaced apart from the retainer projectionand supported for rotational movement about the steering axis to varythe turning angle. The trailing frame, in the restrained position, isconfigured to abut against the retainer projection to restrain thecloser frame at a substantially fixed turning angle.

The details of one or more embodiments are set forth in the accompanyingdrawings and the description below. Other features and advantages willbecome apparent from the description, the drawings, and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear perspective view of a towing work vehicle and a towedwork vehicle with a plurality of row units according to exampleembodiments of the present disclosure;

FIG. 2 is a perspective view of a row unit of the work vehicle of FIG. 1according to example embodiments of the present disclosure;

FIG. 3 is a top view of the row unit of FIG. 2;

FIG. 4 is a side view of a portion of the row unit shown in anunrestrained position and in a restrained position;

FIG. 5 is a bottom view of the portion of the row unit of FIG. 4;

FIG. 6 is a perspective view of the row unit according to additionalembodiments of the present disclosure;

FIG. 7 is a top view of the row unit of FIG. 6;

FIG. 8 is a side view of the row unit according to additionalembodiments of the present disclosure;

FIG. 9 is a top view of the row unit of FIG. 8;

FIG. 10 is a side view of the row unit according to additionalembodiments of the present disclosure;

FIG. 11 is a perspective view of the row unit of FIG. 10;

FIG. 12 is a side view of the row unit according to additionalembodiments of the present disclosure; and

FIG. 13 is a perspective view of the row unit according to additionalembodiments of the present disclosure.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

The following describes one or more example embodiments of a row unit, awork vehicle with a plurality of row units, methods of manufacture ofthe same, and methods for operating the same, as shown in theaccompanying figures of the drawings described briefly above. Variousmodifications to the example embodiments may be contemplated by one ofskill in the art.

As used herein, unless otherwise limited or modified, lists withelements that are separated by conjunctive terms (e.g., “and”) and thatare also preceded by the phrase “one or more of” or “at least one of”indicate configurations or arrangements that potentially includeindividual elements of the list, or any combination thereof. Forexample, “at least one of A, B, and C” or “one or more of A, B, and C”indicates the possibilities of only A, only B, only C, or anycombination of two or more of A, B, and C (e.g., A and B; B and C; A andC; or A, B, and C).

Furthermore, in detailing the disclosure, terms of direction, such as“forward,” “rear,” “front,” “back,” “lateral,” “horizontal,” and“vertical” may be used. Such terms are defined, at least in part, withrespect to the direction in which the work vehicle or implement travelsduring use. The term “forward” and the abbreviated term “fore” (and anyderivatives and variations) refer to a direction corresponding to thedirection of travel of the work vehicle, while the term “aft” (andderivatives and variations) refer to an opposing direction.

The following describes one or more example implementations of thedisclosed work vehicle, as shown in the accompanying figures of thedrawings described briefly above. Generally, the disclosed work vehicleincludes at least one row unit with a row unit frame that supports oneor more closer implements (e.g., a closer disc). The row unit framesupports the closer implements for rotation about a substantiallyvertical axis (i.e., steer axis). Accordingly, the closer implements mayturn to follow and close a non-linear trench, furrow, etc. The closerimplements may also turn about the vertical axis (i.e., a steering axis)to more closely follow trenches that extend along a side sloping hill.

The row unit of the present disclosure may include additional featuresthat provide certain advantages. For example, the row unit may include awalking beam construction that couples the closer implements and allowsthe closer implements to rotationally move as a unit relative to theground surface, e.g., to overcome obstacles and avoid jamming of thecloser implements. Also, the row unit may include a retainer thatrestrains the closer implements at a predetermined steering angle andthat selectively releases the closer implements for rotation about thesteering axis. This may provide convenience, for example, when stowingand transporting the row unit. Additionally, the row unit may includeone or more features that bias the row unit toward a predetermined turnangle (e.g., toward a straight-ahead or zero degree turn angle) toimprove function of the closer implements. Still further, the row unitmay include features that actuate to automatically change the steeringangle of the closer implements. In some embodiments, a sensor unit maybe included for detecting how the trench turns ahead of the closerimplements, and the actuator may actuate the closer implementsaccordingly. Moreover, the row unit may include features thatautomatically change the height of the closer implements relative to theground surface and/or that automatically vary the downforce applied bythe closer implements onto the ground surface.

Thus, the row unit of the present disclosure may reliably and accuratelyclose the trench during planting and other related operations.Furthermore, the row unit may provide convenient use as will bediscussed.

FIG. 1 illustrates a work vehicle 100 according to example embodimentsof the present disclosure. The work vehicle 100 may be towed by anothervehicle, such as a tractor 101. Thus, the work vehicle 100 may be atowed work vehicle. In other embodiments, the work vehicle 100 of thepresent disclosure may be a self-propelled vehicle. In some embodiments,the work vehicle 100 may be a planter or seeder configured foragricultural work. It will be appreciated that the illustrated workvehicle 100 is an example embodiment. One or more features of thepresent disclosure may be included on a different work vehicle withoutdeparting from the scope of the present disclosure.

The work vehicle 100 includes a front end 114 and a rear end 116. Thework vehicle 100 also includes a first side 120 and a second side 122.The work vehicle 100 defines a longitudinal axis 118, which may extendbetween the rear end 116 and the front end 114. It will be appreciatedthat a straight-ahead travelling direction of the work vehicle 100 mayextend along the longitudinal axis 118 from the rear end 116 toward thefront end 114. The work vehicle 100 further defines a lateral axis 124extending between the first side 120 and the second side 122.Furthermore, the work vehicle 100 defines a vertical axis 126, whichextends normal to the longitudinal axis 118 and the lateral axis 124.The vertical axis 126 may extend normal to a ground surface (soil,earth, etc.). As will be discussed, the work vehicle 100 may, at times,turn substantially about the vertical axis 126 to navigate across afield. Thus, the vertical axis 126 may be referred to as a steering axisor a yaw axis.

The work vehicle 100 may include a frame structure 110 (i.e., achassis). The frame structure 110 may include an elongate tongue 111.The tongue 111 may be a rigid or telescoping beam that extends along thelongitudinal axis 118. The tongue 111 may include a towing package forhitching and unhitching from the tractor 101. The frame structure 110may further include a lateral beam 117. The lateral beam 117 may be arigid member that extends along the lateral axis 124. The lateral beam117 may be fixed to the tongue 111 of the frame structure 110, proximatethe rear end 116 of the work vehicle 100.

The work vehicle 100 may also include a commodity system 129 with atleast one tank 131 and a commodity distribution system 133. The tank 131may contain a bulk amount of a commodity (e.g., seed, fertilizer, etc.),and the distribution system 133 may include hoses, lines, etc. that areconfigured to distribute the commodity from the tank 131 to a pluralityof row units 119. The commodity system 129 may also include a meteringsystem that meters out the commodity at a predetermined rate.

The row units 119 may be attached to the lateral beam 117 of the framestructure 110. The row units 119 may branch rearward from the lateralbeam 117 to define much of the rear end 116 of the work vehicle 100. Theplurality of row units 119 may be substantially similar to each otherand may include a first row unit 121, a second row unit 123, a third rowunit 125, and so on, across the rear end 116 and along the lateral axis124. In some embodiments, the row units 119 may be configured to: 1)open a trench, furrow, or other ground opening as the work vehicle 100moves through a field; 2) deposit seed, fertilizer, or other commoditywithin the opening; and 3) close the ground opening by moving soiland/or other materials back into the opening to thereby plant thecommodity therein.

The first row unit 121 may be a representative example of the other rowunits 119. The first row unit 121 may include a row unit frame 130. Therow unit frame 130 may include a plurality of strong and rigid brackets,linkages, fasteners, etc., that support other components that will bediscussed. The row unit frame 130 may be attached to the frame structure110. For example, the row unit frame 130 may be attached to the lateralbeam 117 and may extend rearward therefrom.

The first row unit 121 may also include a ground system 132. The groundsystem 112 may include one or more gauge wheels 134 that are attached tothe row unit frame 130. The ground system 132 may also include one ormore ground engaging implements that move soil (e.g., to create andclose a trench as the vehicle 100 moves across the field). Specifically,in some embodiments, the ground system 132 may include one or moreopener implements 136 (e.g., opener discs or wheels) and one or morecloser implements 138 (i.e., closer discs or wheels). Generally, as thevehicle 100 travels, the opener implements 136 may open a trench in thesoil, seed may be deposited in the open trench, and the closerimplements 138 may close the trench over the seed. Additionally, thegauge wheels 134 may ride on the surface of the ground as the vehicle100 travels, maintaining a set vertical position of the row unit 121above the ground. Thus, the gauge wheels 134 may maintain a set depth ofthe furrow created by the opener implements 136.

At least part of the first row unit 121 may be supported for rotationalmovement about a substantially vertical axis of rotation 140 relative toother portions of the work vehicle 100. In particular, the closerimplements 138 may be supported for travel along the ground along acurved path because components are supported for rotation about the axis140. Thus, as the work vehicle 100 turns within the field and the openerimplements 136 create a curved trench for the seed, fertilizer, etc. Thecloser implements 138 may follow the curved trajectory of the trench andeffectively close the trench over the seed, fertilizer, etc.

In some embodiments, the axis of rotation 140 of the row unit 121 may beparallel to the vertical axis 126 of the work vehicle 100. In otherembodiments, the axis of rotation 140 may be “substantially parallel,”meaning that the axis of rotation 140 intersects the vertical axis 126but allows the row unit 121 to pivot as the work vehicle 100 turnswithin the field and/or as the trench or other ground opening curves andchanges trajectory through the field. In some embodiments, the axis ofrotation 140 is within approximately thirty-five degrees (35°) of thevertical axis 126.

Additionally, in some embodiments, the first row unit 121 may besupported for rotational movement about the axis 140 relative to thelateral beam 117 of the work vehicle 100. In additional embodiments, therow unit 121 may include a forward assembly 148 and a closer assembly150. The forward assembly 148 may be attached to the lateral beam 117 ofthe work vehicle 100, and the forward assembly 148 may support the gaugewheels 134 and the opener implements 136. The closer assembly 150 maysupport the closer implements 138 of the row unit 121. The closerassembly 150 may be attached to the forward assembly 148 and may bedisposed rearward with respect thereto. The closer assembly 150 may bepivotally coupled to the forward assembly 148 for relative rotationabout the axis of rotation 140.

As represented in FIG. 1, the closer assembly 150 may turn between afirst position (shown in solid lines) and a second position (shown inphantom). In some embodiments, the first position may be a“straight-ahead position” wherein a longitudinal axis 128 of the closerassembly 150 is oriented substantially normal to the lateral beam 117.In contrast, the longitudinal axis 128 in the second “turned” positionmay be disposed at an angle relative to the lateral beam 117. It will beappreciated that the closer assembly 150 may be configured for turningclockwise and counterclockwise (in opposite directions) about the axisof rotation 140. As the row unit 121 turns about the axis 140, a turningangle 142 of the closer assembly 150 may vary.

Referring now to FIGS. 2-5, the first row unit 121 will be discussed infurther detail according to example embodiments. It will be understoodthat the first row unit 121 may be substantially similar to the secondrow unit 123, the third row unit 125, and/or any of the other row units119.

The row unit 121 may generally include the forward assembly 148 and thecloser assembly 150, which may be rotationally attached at a rotationaljoint 192. Accordingly, the closer assembly 150 may rotate about thesubstantially vertical steering axis 140.

In some embodiments, the forward assembly 148 may include a forwardframe 144 with a linkage 180. The linkage 180 may be a casting with abar-like forward end 181. The forward end 181 may include one or moreprojections, through-holes, or other features used for attaching toother members of the forward frame 144 of the forward assembly 148.Furthermore, the linkage 180 may define a forward longitudinal axis 183.In some embodiments, the forward longitudinal axis 183 may besubstantially horizontal and may be substantially parallel to thelongitudinal axis 118 of the work vehicle 100. The linkage 180 mayfurther include a rear body 184 that defines a receiver tube 186 that iscentered about the axis of rotation 140. The receiver tube 186 maypartly define the rotational joint 192

As shown in FIGS. 2, 4, and 5, the linkage 180 of the forward frame 144may also include a first projection 216 and a second projection 218. Thefirst projection 216 and the second projection 218 may be elongate tinesor tangs that extend generally rearward from opposite sides of the rearbody 184. As shown in FIG. 5, the first and second projections 216, 218may be disposed on opposite sides of the axis of rotation 140 and mayextend rearward therefrom. Also, the first and second projections 216,218 may curve inward toward the longitudinal axis 183 at their terminalends.

Referring back to FIG. 2, the closer assembly 150 will now be discussedin detail according to example embodiments. For example, the closerassembly 150 may include a closer frame 146 (i.e., a rear frame). Thecloser frame 146 may include a linkage 190 and a trailing frame 188. Thelinkage 190 may be rotationally attached to the linkage 180 of theforward frame 144 at the rotational joint 192. Also, the trailing frame188 may be moveably coupled to the linkage 190 as will be discussed.

The linkage 190 may be a rigid member constructed from metal in someembodiments. The linkage 190 may be manufactured from a casting processin some embodiments. The linkage 190 may include a forked end 210, arelatively flat body 212, and a projection 214. The projection 214 mayproject downward from the body 212 from a side that is opposite theforked end 210. The forked end 210 may be attached to the forward frame144 to define the rotational joint 192. The rotational joint 192 mayalso include a pin 194 that is received in the forked end 210 of thelinkage 190 and within the receiver tube 186 of the forward frame 144.Thus, the linkage 190 (and the rearward components of the closerassembly 150) may rotate about the axis of the pin 194 (i.e., the axisof rotation 140) to vary the steering angle 142 of the closer assembly150. In some embodiments, this may define a single axis of rotation(i.e., the axis 140).

The trailing frame 188 may be a rigid member constructed from metal insome embodiments. The trailing frame 188 may be saddle-shaped and mayinclude a top side 222, a first lateral side 224, and a second lateralside 226. The trailing frame 188 may also include a forward attachmentportion 220 that protrudes forward from the first lateral side 224 andthe second lateral side 226. The forward attachment portion 220 mayreceive the forked end 210 of the linkage 190 and may be attachedthereto. For example, the forward attachment portion 220 may bepivotally attached to the forked end 210 at a lift joint 230 forrotation about a first lateral axis 232.

Furthermore, the trailing frame 188 may include a drop member 228. Thedrop member 228 may be a rigid member constructed from metal in someembodiments. The drop member 228 may be forked. The drop member 228 mayalso be fixed to the first lateral side 224 and the second lateral side226. The drop member 228 may define an abutment member 229. The abutmentmember 229 may be defined on a downward-facing surface between the forksof the drop member 228.

The closer assembly 150 may additionally include a biasing member 191.The biasing member 191 may be a helical spring in some embodiments. Thebiasing member 191 may be a tension spring in some embodiments. Thebiasing member 191 may be attached at one end to the underside of thetrailing frame 181. The biasing member 191 may also be attached at theopposite end to the projection 214 of the linkage 190. The biasingmember 191 may bias and pull the trailing frame 188 toward the linkage190 as the trailing frame 188 pivots about the first lateral axis 232.

Additionally, the closer assembly 150 may include a closer implementassembly 235. The closer implement assembly 235 may generally includethe closer implement(s) 138 mentioned above with respect to FIG. 1. Morespecifically, in some embodiments, the closer implement assembly 235 mayinclude a first closer disc 201 and a second closer disc 202. The closerimplement assembly 235 may also include a walking beam construction 204,which is attached to the first and second closer discs 201, 201, andwhich is also attached to the closer frame 146.

The first closer disc 201 may include a hub 234, which is attached to afirst mount 246 (a first area or first end) of the walking beamconstruction 204. The second closer disc 202 may include a hub 240 thatis attached to a second mount 248 (a second area or second end) of theof the walking beam construction 204. The walking beam construction 204may also include an elongate beam 250 that extends between the firstmount 248 and the second mount 250.

The walking beam construction 204 may be received between the open,forked end of the drop member 228 of the trailing frame 188. Forexample, an intermediate area of the beam 250 (e.g., a midpoint betweenthe first and second mounts 246, 248) may be rotationally attached tothe forked end of the drop member 228 of the closer frame 146. As such,the closer implement assembly 235 (the first and second discs 201, 202and the walking beam construction 204) may rotate as a unit relative tothe drop member 228 about a horizontal axis of rotation that extendslaterally.

As shown, the first closer disc 201 (the leading disc) may be spacedlongitudinally forward from the second closer disc 202, and the walkingbeam construction 204 may extend substantially along the longitudinalaxis 128. Also, the first and second closer discs 201, 202 may bedisposed on opposite sides of the longitudinal axis 128. Furthermore,the first and second closer discs 201, 202 may be tilted and angled fromtop to bottom such that the respective bottom edge is disposed closer tothe longitudinal axis 128 than the opposing top edge.

Additionally, as shown in FIG. 3, the first closer disc 201 may bedisposed at a so-called “toe-out” angle 237 such that a leading edge 236is disposed further away from the longitudinal axis 128 than a trailingedge 238 thereof. In contrast, a leading edge 242 and a trailing edge244 of the second closer disc 202 may be disposed at a substantiallyequal distance from the longitudinal axis 128.

During operation, the opener implements 136 may open a trench into whichthe row unit 121 deposits the seed, fertilizer, or other commodity. Thefirst closer disc 201 may push earth, soil, etc. into the trench fromone side, and the second closer disc 202 may push earth, soil, etc. intothe trench from the opposite side to bury the commodity therein and toclose the trench.

Because the first closer disc 201 is disposed at the toe-out angle 237,the first closer disc 201 may continuously tend to pull the closerassembly 150 laterally to some degree. For example, a portion of thefirst closer disc 201 may be received within the trench, but the toe-outangle 237 may cause the first closer disc 201 to continuously climb outof the trench while it moves material into the trench. Accordingly, thetoe-out angle 237 of the first closer disc 201 may act to maintain thecloser assembly 150 centered over the trench and/or in position toeffectively move material into the trench.

Furthermore, the work vehicle 100 may move straight ahead in many casessuch that the open trench extends along a substantially straighttrajectory. However, the work vehicle 100 may turn and travel through acurve such that the trench curves along a non-linear trajectory.Regardless, the closer assembly 150 may rotate about the vertical axisof rotation 140 to thereby follow the curved trajectory of the opentrench. Accordingly, the closer assembly 150 may remain in position toeffectively close the trench.

In addition, if the first closer disc 201 impacts an obstacle (e.g., arock, stump, root, etc.), the closer implement assembly 235 may rotate.Specifically, the impact may cause rotation of the walking beamconstruction 250, lifting the first closer disc 201 off the ground anddriving the second closer disc 202 toward the ground. Once the firstcloser disc 201 has cleared the obstacle, the walking beam construction250 may rotate in the reverse direction causing the first closer disc201 to move back toward the ground and the second closer disc 202 tomove away from the ground. Accordingly, the closer implement assembly235 may “walk over” the obstacle due to rotation of the walking beamconstruction 250.

Furthermore, in some embodiments, the closer assembly 150 may includethe abutment member 229. The abutment member 229 may be fixed to thecloser frame 146 and may abut against the closer implement assembly 235to limit its range of rotational movement. In some embodiments, theabutment member 229 may be an underside surface between the forks of theforked drop member 228. The abutment member 229 may be configured toabut against the opposing top surface of the beam 250 of the walkingbeam construction 204. For example, as the first closer disc 201 raisesfrom the ground and the second closer disc 202 rotates toward theground, the beam 250 may eventually abut against the abutment member 229of the drop member 228. Thus, the abutment member 229 may limitover-rotation (e.g., preventing the closer implement assembly 235 frommoving over center). Accordingly, the closer implement assembly 235 mayremain in position such that the closer discs 201, 202 can effectivelyclose the trench.

Moreover, the closer implement assembly 235 may include a projection 252that is configured to move (push) an obstacle out of the way. As shownin FIG. 2, the projection 252 may include an attachment portion 254,which is fixed to the beam 250, and an opposing terminal end portion256. The attachment portion 254 may be attached at an intermediate pointof the beam 250 between the first mount 246 and the area where the beam250 is attached to the drop member 228. The projection 252 may beintegrally connected with the beam 250 so as to be unitary therewith.Furthermore, projection 252 may project downward from the beam 250toward the ground. Also, the projection 252 may be tapered (e.g.,triangular) with the attachment portion 254 being wider than the pointedterminal end portion. As the closer assembly 150 travels, the projection252 may impact an obstacle, such as a root, a rock, etc. The projection252 may, in turn, push the obstacle away from the closer implementassembly 235. In addition or instead, the impact may rotate the closerimplement assembly 235, pushing the first closer disc 201 upward anddriving the second closer disc 202 toward the ground. Thus, the obstacleis unlikely to jam between the closer discs 201, 202 or otherwiseinhibit closing of the trench.

As noted above, the trailing frame 188 may be rotationally attached tothe linkage 190 at the lift joint 230. Accordingly, the trailing frame188 may be rotated at the lift joint 230 to vary the height of the firstand second closer discs 201, 202 and/or to vary the force the closerdiscs 201, 202 impart to the ground. The biasing member 191 may bias thetrailing frame 188 toward the linkage 190 (i.e., toward a loweredposition).

The row unit 121 may further include a retainer 203. The retainer 203may comprise the first projection 216 and the second projection 218 ofthe linkage 180 of the forward assembly 148. The retainer 203 may alsocomprise the first lateral side 224 and the second lateral side 226 ofthe trailing frame 188. The retainer 203 may additionally comprise thebiasing member 191. As represented in FIG. 4, the closer assembly 150may rotate relative to the linkage 190 (and the linkage 180) between anunrestrained position (shown in solid lines) and a restrained position(shown in phantom).

In the unrestrained position, the closer discs 201, 202 may push on theground, causing the trailing frame 288 to rotate away from the linkage190 against the biasing force provided by the biasing member 191. Also,in this unrestrained position, the first and second lateral sides 224,226 of the trailing frame 188 may be spaced apart at a clearancedistance 205 away from the first and second projections 216, 218 of theforward frame 144.

In contrast, in the restrained position shown in phantom in FIG. 4, thecloser discs 201, 202 may be raised from the ground. For example, theentire closer assembly 150 may be lifted from the ground and stowed tofacilitate transport of the work vehicle 100. Since the closer discs201, 202 are removed from the ground, the biasing member 191 may biasthe trailing frame 188 toward the linkage 190. This causes the lateralsides 224, 226 to move over the first and second projections 216, 218 ofthe linkage 180. Accordingly, abutment between the lateral sides 224,226 and the projections 216, 218 may limit rotation of the trailingframe 188 about the vertical axis of rotation 140. In some embodiments,when in the restrained position, the closer assembly 150 may be disposedat a substantially fixed steering angle relative to the forward assembly148 and/or other portions of the work vehicle 100. For example, in therestrained position, the closer assembly 148 may be disposed at astraight ahead, zero-degree (0°) turning angle between the longitudinalaxis 128 of the closer assembly 150 and the longitudinal axis 183 of theforward assembly 148.

It will be appreciated that the retainer 203 may be configureddifferently from the illustrated embodiments without departing from thescope of the present disclosure. For example, in an additionalembodiment, the projections 216, 218 may be attached to and may projectforward from the closer frame 146 toward the forward frame 144. When inthe restrained position, the projections 216, 218 may abut the forwardframe 144 to limit rotation of the closer frame 146 and retain thecloser assembly 150 at a substantially fixed steering angle.

Accordingly, the retainer 203 may retain the closer assembly 150 inplace. This may be useful, for example, when transporting the workvehicle 100.

Referring now to FIGS. 6 and 7, the row unit 321 of the presentdisclosure will be discussed according to additional embodiments. Therow unit 321 of FIGS. 6 and 7 may be substantially similar to theembodiments of FIGS. 1-5 except as noted below. Components of FIGS. 1-5may also be shared and combined with those discussed below. Componentsthat correspond to those of the embodiments of FIGS. 1-5 will beindicated with corresponding reference numbers increased by 200.

As shown, the row unit 321 may include the forward assembly 348 and thecloser assembly 350 attached at the rotational joint 392. Accordingly,the closer assembly 350 may rotate relative to the forward assembly 348about the vertical axis of rotation 340. Specifically, the linkage 380of the forward assembly 348 may be rotationally attached at therotational joint 392 to the linkage 390 of the closer assembly 350.

The linkage 390 may include a first projection 466 and a secondprojection 467. The first projection 466 may be integrally attached toand may project laterally away from the linkage 390. The secondprojection 467 may be symmetrically disposed and attached to theopposite side of the linkage 390.

The trailing frame 388 of the closer assembly 350 may be rotationallyattached to the linkage 390 as discussed above. As shown, the first andsecond closer discs 401, 402 may be attached to opposite sides of thetrailing frame 388. Also, the first and second closer discs 401, 402 maybe aligned longitudinally (FIG. 7).

The row unit 321 may further include a sensor assembly 460. The sensor460 may detect a change in trajectory of the trench in order to move thecloser assembly 350 and change the steering angle of the closer assembly350 about the axis 340.

In some embodiments, the sensor 460 may include a wheel 461 and asupport 462 that attaches the wheel 461 to the row unit 321. The wheel461 may be disposed between the first and second closer discs 401, 402and may be configured to ride within the trench. Also, the support 461may include linkages, brackets, fasteners, biasing members, springs, andother accessories that extend upward from the axle of the wheel 461 andthat attaches to an actuator 463. In some embodiments, the wheel 461 andthe support 461 may be supported for rotation about the axis of rotation340, independent of the closer assembly 350 and the forward assembly348.

The actuator 463 may be of a variety of types without departing from thescope of the present disclosure. For example, the actuator 463 may be apneumatic actuator, which includes a valve system, fluid lines, etc.that are supported on the forward assembly 348. The actuator 463 mayalso include a first inflatable bladder 464 and a second inflatablebladder 465. In some embodiments, the support 462 of the sensor may beoperably connected to one or more valves of the actuator 463.

As such, when the support 462 rotates one way about the axis of rotation340, one bladder 464, 465 inflates and the other deflates. In FIG. 7,the first bladder 464 is inflating to push the projection 466 and therest of the closer assembly 350 about the axis of rotation 340. Incontrast, when the support 462 rotates the opposite way, the secondbladder 465 inflates, pushing the projection 467 and the rest of thecloser assembly 350 in the opposite direction about the axis of rotation340.

Accordingly, the steering angle of the closer assembly 350 may beactively controlled according to the input provided by the sensorassembly 460. In other words, the wheel 461 may rotate about the axis340 as the trench curves and changes trajectory. The closer assembly 350may receive this input to rotate the closer assembly 350 about the axis340 accordingly.

Referring now to FIGS. 8 and 9, the row unit 521 of the presentdisclosure will be discussed according to additional embodiments. Therow unit 521 of FIGS. 8 and 9 may be substantially similar to theabove-described embodiments except as noted below. Components discussedabove may also be combined with those discussed below. Components thatcorrespond to those of the embodiments of FIGS. 6 and 7 will beindicated with corresponding reference numbers increased by 200.

As shown, the row unit 521 may include the forward assembly 548 and thecloser assembly 550 attached at the rotational joint 592. Accordingly,the closer assembly 550 may rotate relative to the forward assembly 548about the vertical axis of rotation 540. Specifically, the linkage 580of the forward assembly 548 may be rotationally attached at therotational joint 592 to the linkage 590 of the closer assembly 550.

The linkage 580 may include a forked end 670 with an upper member 671and a lower member 672. The linkage 580 may also include a first stop668 and a second stop 669. The first and second stops 668, 669 may beposts that project rearward from the linkage 580.

The closer assembly 550 may include the linkage 590. The linkage 590 mayinclude a first ramp surface 674. The closer assembly 550 may furtherinclude the trailing frame 588. The first and second closer discs 601,602 may be attached to the trailing frame 588.

The rotational joint 592 may include the pin 594, which extends throughthe upper member 671 and the lower member 672 of the forked end 670 ofthe linkage 580 as well as the linkage 590. The rotational joint 592 mayfurther include a ramp member 673. The ramp member 673 may include asecond ramp surface 675. The second ramp surface 675 may be inverse tothe first ramp surface 674 of the linkage 590 in some embodiments.Moreover, the rotational joint 592 may include a biasing member 676. Thebiasing member 676 may be a spring, such as a wave spring that extendsabout the pin 594 between the lower member 672 of the linkage 580 andthe linkage 590.

The second ramp surface 675 may abut and may oppose the first rampsurface 674. As the closer assembly 550 rotates about the axis 540, thesecond ramp surface 675 may cam against the first ramp surface 674,causing compression of the biasing member 676. The biasing member mayresiliently bias the closer assembly 550 back toward a zero degree (0°)steering angle such that the ramp surfaces 674, 675 overlap once again.In other words, the closer assembly 550 may self-center due to thebiased rotational joint 592.

Referring now to FIGS. 10 and 11, the row unit 721 of the presentdisclosure will be discussed according to additional embodiments. Therow unit 721 of FIGS. 10 and 11 may be substantially similar to theabove-described embodiments except as noted below. Components discussedabove may also be combined with those discussed below. Components thatcorrespond to those of the embodiments of FIGS. 8 and 9 will beindicated with corresponding reference numbers increased by 200.

As shown, the row unit 721 may include the forward assembly 748 and thecloser assembly 750 attached at the rotational joint 792. Accordingly,the closer assembly 750 may rotate relative to the forward assembly 748about the vertical axis of rotation 740. Specifically, the linkage 780of the forward assembly 748 may be rotationally attached at therotational joint 792 to the linkage 790 of the closer assembly 750.

The row unit 721 may also include a mount 880 (FIG. 11). The mount 880may include rigid brackets that are fixed to the underside of thetrailing frame 788. The first and second closer discs 801, 802 may beattached to the trailing frame 788, and the mount 880 may be disposedtherebetween. The trailing frame 788 may also extend longitudinally fromthe trailing frame 788.

The row unit 721 may additionally include a press wheel assembly 811.The press wheel assembly 811 may include a wheel 882 and a mount 883.The mount 883 may include a collection of rigid brackets, connectors,etc. The mount 883 may be attached on one end to the hub of the wheel882 and on the opposite end to the mount 880 (FIG. 11). The mount 883may be rotationally attached to the mount 880 at a lateral joint 884.

In addition, the row unit 721 may include an actuator 885. The actuator885 may be of a variety of types, such as an electric actuator, such asa motorized linear actuator. The actuator 885 may also comprise apneumatic actuator or a hydraulic actuator without departing from thescope of the present disclosure. In some embodiments, the actuator 885may be operatively attached to both the mount 883 and the mount 880(FIG. 11). As shown, the actuator 885 may actuate a rod 886 tocoincidentally change the angle between brackets and to ultimatelychange an angle of rotation between the mount 880 and the mount 883.Accordingly, as the actuator 885 actuates, the height of the wheel 882changes which, in turn, controls the depth that the closer discs 801,802 operate.

In addition, the work vehicle 100 may include a control system 887. Thecontrol system 887 may be configured for controlling the actuator 885.The control system 887 is shown in FIG. 10 according to exampleembodiments. It will be understood that FIG. 10 is a simplifiedrepresentation of the control system 887 for purposes of explanation andease of description, and FIG. 10 is not intended to limit theapplication or scope of the subject matter in any way. Practicalembodiments of the control system 887 may vary from the illustratedembodiment without departing from the scope of the present disclosure.Also, the control system 887 may include numerous other devices andcomponents for providing additional functions and features, as will beappreciated in the art.

The control system 887 may be wholly supported on the work vehicle 100,or the control system 887 may include components that are remote fromthe vehicle 100. The control system 887 may be an electronic (e.g.,computerized) control system in some embodiments. In other embodiments,the control system 887 may be a hydraulic control system, a pneumaticcontrol system, a combination control system, etc.

The control system 887 may include a processor 888. The processor 888may comprise hardware, software, and/or firmware components configuredto enable communications and/or interaction between sensor(s) of the rowunit 721, the actuator 885 of the row unit 721, as well as a memoryelement, a user interface (U/I), etc. The processor 888 may also performadditional tasks and/or functions described in greater detail below.Depending on the embodiment, the processor 888 may be implemented orrealized with a general purpose processor, a content addressable memory,a digital signal processor, an application specific integrated circuit,a field programmable gate array, any suitable programmable logic device,discrete gate or transistor logic, processing core, discrete hardwarecomponents, or any combination thereof, designed to perform thefunctions described herein. The processor 888 may also be implemented asa combination of computing devices, e.g., a plurality of processingcores, a combination of a digital signal processor and a microprocessor,a plurality of microprocessors, one or more microprocessors inconjunction with a digital signal processor core, or any other suchconfiguration. In practice, the processor 888 includes processing logicthat may be configured to carry out the functions, techniques, andprocessing tasks associated with the operation of the control system887. Furthermore, the steps of a method or algorithm described inconnection with the embodiments disclosed herein may be embodieddirectly in hardware, in firmware, in a software module executed by theprocessor 888, or in any practical combination thereof.

In some embodiments, a user may determine a target position for thecloser discs 801, 802, and the user may enter a corresponding usercommand with a user interface. The user may enter the command using abutton, dial, voice command, joystick or other element of the userinterface. The processor 888 may receive a corresponding input from theuser interface, and the processor 888 may generate a command foractuating the actuator 885 according to the target position. In someembodiments, the control system 887 may also include a sensor thatdetects an actual position of one or more components of the closerassembly 750 and provides a feedback signal to the processor 888 forclosed loop control.

Referring now to FIG. 12, the row unit 921 of the present disclosurewill be discussed according to additional embodiments. The row unit 921of FIG. 12 may be substantially similar to the above-describedembodiments except as noted below. Components discussed above may alsobe combined with those discussed below. Components that correspond tothose of the embodiments of FIGS. 10 and 11 will be indicated withcorresponding reference numbers increased by 200.

As shown, the row unit 921 may include the forward assembly 948 and thecloser assembly 950 attached at the rotational joint 992. Accordingly,the closer assembly 950 may rotate relative to the forward assembly 948about the vertical axis of rotation 940. Specifically, the linkage 980of the forward assembly 948 may be rotationally attached at therotational joint 992 to the linkage 990 of the closer assembly 950.

The trailing frame 988 may be rotationally attached to the linkage 990,and at least one closer disc 1001 may be attached to the trailing frame988. The actuator 1085 may be attached to an upper projection of thetrailing frame 988 and a lower projection of the linkage 990. Theactuator 1085 may include a biasing member 1090, such as a helicalspring (e.g., a tension spring). The actuator 1085 may actuate to changea biasing force (e.g., tension) provided by the biasing member 1090.This may selectively change the downforce applied by the closer disc1001 on the ground and/or the height of the closer disc 1001. Thecontrol system 1087 may also be included and may be used for controllingactuation of the actuator 1085.

Referring now to FIG. 13, the row unit 1121 of the present disclosurewill be discussed according to additional embodiments. The row unit 1121of FIG. 13 may be substantially similar to the above-describedembodiments except as noted below. Components discussed above may alsobe combined with those discussed below. Components that correspond tothose of the embodiments of FIG. 12 will be indicated with correspondingreference numbers increased by 200.

As shown, the row unit 1121 may include the forward assembly 1148 andthe closer assembly 1150 attached at the rotational joint 1192.Accordingly, the closer assembly 1150 may rotate relative to the forwardassembly 1148 about the vertical axis of rotation 1140. Specifically,the linkage 1180 of the forward assembly 1148 may be rotationallyattached at the rotational joint 1192 to the linkage 1190 of the closerassembly 1150. The first and second closer discs 1201, 1202 may beattached to the trailing frame 988.

The actuator 1285 may be attached to an upper projection off the linkage1190 and attached to the trailing frame 1188. The actuator 1285 may be apneumatic actuator in some embodiments and may be attached to theprocessor 1288 of the control system 1287 as shown.

Also, the following examples are provided, which are numbered for easierreference.

1. A row unit for a work vehicle, the work vehicle defining a vehiclelongitudinal axis, the row unit configured to be attached to the workvehicle with a plurality of other row units for movement across a field,the row unit comprising: a row unit frame including a closer frame, thecloser frame defining a longitudinal axis and a transverse axis, thecloser frame being supported for rotational movement about asubstantially vertical steering axis to vary a turning angle between thelongitudinal axis of the closer frame and the vehicle longitudinal axis;and a closer implement assembly that includes a first closer implement,a second closer implement, and a walking beam construction, the firstcloser implement and the second closer implement attached to oppositeareas of the walking beam construction, the walking beam constructionrotationally attached to the closer frame to support rotation of thecloser implement assembly about the transverse axis, the first closerimplement configured to move ground material into a ground opening fromone side as the work vehicle moves across the field, the second closerimplement configured to move ground material into the ground openingfrom an opposite side as the work vehicle moves across the field.

2. The row unit of example 1, further comprising an abutment member thatis fixedly attached to the closer frame, wherein the abutment member isconfigured to abut against the closer implement assembly to limitrotational movement of the closer implement assembly about thetransverse axis.

3. The row unit of example 1, wherein at least one of the first closerimplement and the second closer implement includes a leading edge and atrailing edge with respect to the longitudinal axis; and wherein firstcloser implement is supported at a toe-out angle such that the leadingedge is disposed further away laterally from the longitudinal axis ofthe closer frame than the trailing edge.

4. The row unit of example 3, wherein the first closer implement isdisposed forward of the second closer implement along the longitudinalaxis of the closer frame; and wherein the first closer implementincludes the leading edge and the trailing edge.

5. The row unit of example 1, wherein the row unit frame includes aforward frame and the closer frame; wherein the forward frame isconfigured to be attached to a work vehicle frame of the work vehicle;wherein the closer frame is rotationally attached to the forward frameat a rotational joint, the rotational joint supporting the closer framefor rotational movement relative to the forward frame about thesubstantially vertical steering axis.

6. The row unit of claim 5, wherein the forward frame supports at leastone of a gauge wheel and an opener implement of the row unit.

7. The row unit of example 1, wherein the walking beam constructionincludes a beam with a first end and a second end; wherein the first endand the second end are spaced apart along the longitudinal axis of thecloser frame; wherein the first end is attached to the first closerimplement and the second end is attached to the second closer implement;and further comprising a projection that projects in a downwarddirection from the beam, the projection configured to move anobstruction away from the beam as the work vehicle moves across thefield.

8. The row unit of example 9, wherein the projection includes anattachment portion that is attached to the beam and a terminal endportion that is spaced apart from the beam; and wherein the projectionis tapered between the attachment portion and the terminal end portionsuch that a dimension of the projection at the attachment portion isgreater than the dimension of the projection at the terminal endportion.

9. A row unit for a work vehicle, the row unit configured to be attachedto the work vehicle with a plurality of other row units for movementacross a field, the row unit comprising: a forward frame defining aforward longitudinal axis, the forward frame configured to attach to awork vehicle frame of the work vehicle; a closer frame defining a closerlongitudinal axis, the closer frame rotationally attached to the forwardframe and supported for rotational movement about a substantiallyvertical steering axis to vary a turning angle between the closerlongitudinal axis and the forward longitudinal axis; and a closerimplement attached to the closer frame, the closer implement configuredto move ground material into a ground opening as the work vehicle movesacross the field; the closer frame supported for movement relative tothe forward frame between an unrestrained position and a restrainedposition; the closer frame, in the unrestrained position, beingsupported for rotational movement about the steering axis to vary theturning angle; and wherein the closer frame, in the restrained position,is restrained at a substantially fixed turning angle.

10. The row unit of example 9, wherein the substantially fixed turningangle is a zero-degree turning angle between the closer longitudinalaxis and the forward longitudinal axis.

11. The row unit of example 9, further comprising a retainer attached toone of the forward frame and the closer frame; wherein the retainer, inthe unrestrained position, is disposed a clearance distance away fromthe other of the forward frame and the closer frame during rotation ofthe closer frame relative to the forward frame; and wherein theretainer, in the restrained position, abuts against the other of theforward frame and the closer frame to limit rotation of the closer framerelative to the forward frame.

12. The row unit of example 11, wherein the retainer includes a firstretainer member and a second retainer member that are attached to theone of the forward frame and the closer frame; wherein the firstretainer member, in the restrained position, abuts against the other ofthe forward frame and the closer frame to limit rotation of the closerframe in a first direction; wherein the second retainer member, in therestrained position, abuts against the other of the forward frame andthe closer frame to limit rotation of the closer frame in a seconddirection that is opposite the first direction.

13. The row unit of example 12, wherein the first retainer member is afirst projection that projects from the forward frame; and wherein thesecond retainer member is a second projection that projects from theforward frame.

14. The row unit of example 11, wherein the retainer is attached to theforward frame; wherein the closer frame is supported for substantiallyvertical movement between the restrained position and the unrestrainedposition relative to the forward frame; wherein, in the unrestrainedposition, the closer frame is disposed the clearance distance away fromthe retainer to allow rotation of the closer frame relative to theforward frame; and wherein, in the restrained position, the closer frameabuts against the retainer to limit rotation of the closer framerelative to the forward frame.

15. The row unit of example 14, further comprising a biasing member thatbiases the closer frame toward the restrained position.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the disclosure.As used herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”and/or “comprising,” when used in this specification, specify thepresence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

The description of the present disclosure has been presented forpurposes of illustration and description, but is not intended to beexhaustive or limited to the disclosure in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of thedisclosure. Explicitly referenced embodiments herein were chosen anddescribed in order to best explain the principles of the disclosure andtheir practical application, and to enable others of ordinary skill inthe art to understand the disclosure and recognize many alternatives,modifications, and variations on the described example(s). Accordingly,various embodiments and implementations other than those explicitlydescribed are within the scope of the following claims.

What is claimed is:
 1. A row unit for a work vehicle, the row unitconfigured to be attached to the work vehicle with a plurality of otherrow units for movement across a field, the row unit comprising: aforward frame defining a forward longitudinal axis, the forward frameconfigured to attach to a work vehicle frame of the work vehicle; acloser frame defining a closer longitudinal axis, the closer framerotationally attached to the forward frame and supported for rotationalmovement about a substantially vertical steering axis to vary a turningangle between the closer longitudinal axis and the forward longitudinalaxis; and a closer implement attached to the closer frame, the closerimplement configured to move ground material into a ground opening asthe work vehicle moves across the field; the closer frame supported formovement relative to the forward frame between an unrestrained positionand a restrained position; the closer frame, in the unrestrainedposition, being supported for rotational movement about the steeringaxis to vary the turning angle; and wherein the closer frame, in therestrained position, is restrained at a substantially fixed turningangle.
 2. The row unit of claim 1, wherein the substantially fixedturning angle is a zero-degree turning angle between the closerlongitudinal axis and the forward longitudinal axis.
 3. The row unit ofclaim 1, further comprising a retainer attached to one of the forwardframe and the closer frame; wherein the retainer, in the unrestrainedposition, is disposed a clearance distance away from the other of theforward frame and the closer frame during rotation of the closer framerelative to the forward frame; and wherein the retainer, in therestrained position, abuts against the other of the forward frame andthe closer frame to limit rotation of the closer frame relative to theforward frame.
 4. The row unit of claim 3, wherein the retainer includesa first retainer member and a second retainer member that are attachedto the one of the forward frame and the closer frame; wherein the firstretainer member, in the restrained position, abuts against the other ofthe forward frame and the closer frame to limit rotation of the closerframe in a first direction; wherein the second retainer member, in therestrained position, abuts against the other of the forward frame andthe closer frame to limit rotation of the closer frame in a seconddirection that is opposite the first direction.
 5. The row unit of claim4, wherein the first retainer member is a first projection that projectsfrom the forward frame; and wherein the second retainer member is asecond projection that projects from the forward frame.
 6. The row unitof claim 3, wherein the retainer is attached to the forward frame;wherein the closer frame is supported for substantially verticalmovement between the restrained position and the unrestrained positionrelative to the forward frame; wherein, in the unrestrained position,the closer frame is disposed the clearance distance away from theretainer to allow rotation of the closer frame relative to the forwardframe; and wherein, in the restrained position, the closer frame abutsagainst the retainer to limit rotation of the closer frame relative tothe forward frame.
 7. The row unit of claim 6, further comprising abiasing member that biases the closer frame toward the restrainedposition.
 8. The row unit of claim 7, wherein the closer frame includesa trailing frame and a linkage; wherein the linkage is pivotallyattached to the forward frame at a rotational joint; wherein the biasingmember is attached to the trailing frame and the linkage; and whereinthe trailing frame is pivotally attached to the linkage and is supportedfor rotational movement between the restrained position and theunrestrained position.
 9. The row unit of claim 1, wherein the closerimplement is a first closer disc of a closer implement assembly; whereinthe closer implement assembly further includes a second closer disc anda walking beam construction; wherein the first closer disc and thesecond closer disc are attached to opposite areas of the walking beamconstruction, the walking beam construction rotationally attached to thecloser frame to support rotation of the closer implement assembly abouta transverse axis, the transverse axis being transverse to the closerlongitudinal axis, the first closer disc configured to move groundmaterial into a ground opening from one side as the work vehicle movesacross the field, the second closer disc configured to move groundmaterial into the ground opening from an opposite side as the workvehicle moves across the field.